Cost-effectiveness of Axicabtagene Ciloleucel and Tisagenlecleucel as Second-line or Later Therapy in Relapsed or Refractory Diffuse Large B-Cell Lymphoma

Abstract

Chimeric antigen receptor (CAR) T cell therapies are approved as a third-line or later therapy for several hematological malignant neoplasms. Recently, randomized clinical trials have investigated their efficacy as a second-line treatment in high-risk relapsed or refractory diffuse large B-cell lymphoma (DLBCL) compared with salvage chemotherapy followed by hematopoietic stem cell transplantation (HSCT). To evaluate the cost-effectiveness of axicabtagene ciloleucel and tisagenlecleucel vs standard care (SC) as second-line or later therapy for relapsed or refractory DLBCL, from both US health care sector and societal perspectives at a cost-effectiveness threshold of $150 000 per quality-adjusted life-year (QALY). This economic evaluation assessed cost-effectiveness using a partitioned survival model with 2021 US dollars and QALYs over a lifetime horizon. Model inputs were derived from 2 randomized clinical trials (ZUMA-7 and BELINDA) and published literature. In the trials, patients who did not respond to SC received CAR T cells (treatment switching or crossover), either outside the protocol (ZUMA-7) or as part of the protocol (BELINDA). A separate scenario analysis compared second-line axicabtagene ciloleucel with SC alone without treatment crossover to CAR T cell therapy. Data analysis was performed from December 18, 2021, to September 13, 2022. CAR T cell therapy (axicabtagene ciloleucel and tisagenlecleucel) compared with salvage chemotherapy followed by HSCT. Costs and QALYs were used to derive incremental cost-effectiveness ratios (ICERs) for the health care sector and societal perspectives. Cost and QALYs were discounted at 3.0% annually. Univariate and multivariate probabilistic sensitivity analysis using 10 000 Monte Carlo simulations were applied to test model uncertainty on the ICER. Second-line axicabtagene ciloleucel was associated with an ICER of $99 101 per QALY from the health care sector perspective and an ICER of $97 977 per QALY from the societal perspective, while second-line tisagenlecleucel was dominated by SC (incremental costs of $37 803 from the health care sector and $39 480 from the societal perspective with decremental QALY of -0.02). Third-line or later tisagenlecleucel was associated with an ICER of $126 593 per QALY from the health care sector perspective and an ICER of $128 012 per QALY from the societal perspective. Based on the scenario analysis of no treatment switching, second-line axicabtagene ciloleucel yielded an ICER of $216 790 per QALY from the health care sector perspective and an ICER of $218 907 per QALY from the societal perspective, compared with SC. When accounting for patients achieving prolonged progression-free survival who would not incur progression-related costs, in this scenario ICER changed to $125 962 per QALY from the health care sector perspective and $122 931 per QALY from the societal perspective. These results were most sensitive to increased list prices of CAR T cell therapy and QALY losses associated with axicabtagene ciloleucel and tisagenlecleucel. These findings suggest that second-line axicabtagene ciloleucel and third-line or later tisagenlecleucel were cost-effective in treating patients with relapsed or refractory DLBCL at the cost-effectiveness threshold of $150 000 per QALY. However, uncertainty remains regarding the best candidates who would experience value gains from receiving CAR T cell therapy.